(188de) Computational Modeling of Biofilm Chemotaxis Induced By a Carbon-Rich Plume in Sediments
AIChE Annual Meeting
Monday, October 29, 2018 - 3:30pm to 5:00pm
In particular, the migration of a biofilm as a whole towards a nutrient source is called biofilm chemotaxis and occurs even if the individual microbes that compose the biofilm are neither chemotactic nor motile. This interesting phenomenon is caused by anisotropic growth with higher rates of cell proliferation and extracellular matrix synthesis along the nutrient concentration gradient. Fluid flow tends to suppress biofilm chemotaxis through metastatic events that involve the downstream relocation of biofilms via creep or detachment. Under certain conditions, biofilms have been experimentally observed to overcome fluid stresses and migrate against the direction of flow in porous media. Yet, the pertinent theoretical analysis has not received the deserved attention.
This work presents a computational demonstration of upstream biofilm migration that is driven by a carbon-rich nutrient supply within a sedimentary porous medium. The process is analyzed at the pore scale with a hybrid computer simulator that combines continuum-based descriptions of fluid flow and solute transport with particle-based descriptions of biofilm growth and detachment (Kapellos et al., 2015). Specifically, the Navier-Stokes-Brinkman equations, poroelasticity equations, and convection-diffusion-reaction equations are solved numerically for the determination of the fluid velocity, biofilm stress, and solute concentration fields. Biofilm growth is described with an on-lattice cellular dynamics model and biofilm metastasis is described with a three-step (crack-roll-flow), on/off-lattice particle transport model. It has been found that biofilms propagate through the pore space and towards the nutrient source as a reactive wave leaving behind oxygen depleted regions filled with inert biomass of apoptotic cells and residual extracellular matrix (Kapellos, 2018).
Acknowledgements: This work has received funding from the European Unionâs Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 741799 (project "OILY MICROCOSM").
Kapellos, G.E. "Computer simulation of upstream biofilm migration in sediments", Frontiers in Environmental Science, under review (2018).
Kapellos, G.E., Alexiou, T.S. and Pavlou, S. "Fluid-biofilm interactions in porous media", In: Becker, S.M. and Kuznetsov, A.V. (Eds.), Modeling of Microscale Transport in Biological Processes, Elsevier, 207-238 (2015).